Process for producing a stretch core spun yarn



D. GLIKSMANN ETAL 3,500,629

PROCESS FOR PRODUCING A STRETCH CORE SPUN YARN March 17, 1970 Filed Dec.6, 1966 n m T M: P w

United States Patent 3,500,629 PROCESS FOR PRODUCING A STRETCH CORE SPUNYARN David Gliksmann, Bronx, N.Y., and David W. Petree, High Point,N.C., assignors to Burlington Industries, Inc., Greensboro, N.C., acorporation of Delaware Filed Dec. 6, 1966, Ser. No. 599,509

Int. Cl. D02g 3/36 US. Cl. 57-144 8 Claims ABSTRACT OF THE DISCLOSURE Aprocess for producing a stretch yarn which coinprises preparing a corespun yarn made up of a core of continuous filament yarn covered withstaple fibers and thereafter false twisting said core spun yarn.

The present invention relates to certain improvements in the texturizingor processing of single ends of yarns comprising staple fibers by falsetwist techniques so as to prepare stretch'yarns. I

Broadly stated, the present invention contemplates (1) preparing a corespun yarn made up of a core of continuous filament yarn covered withstaple fibers which may be 100% nonthermoplastic staple, e.g., woolfibers, 100% thermoplastic staple fibers such as nylon or polyester, orblends of nonthermoplastic and thermoplastic staple; and thereafter (2)false twisting the resulting core spun yarn. This false twistingtreatment may be carried out using conventional false twisting apparatusv and, for example, the conditions employed in Ser. No. 423,256, filedJan. 4, 1965, now US. Patent No. 3,289,401, the subject matter of whichis incorporated herein by reference.

The use of a filament core yarn as proposed herein offers a number ofimportant advantages for the preparation of textured or stretch yarnsfrom staple yarns. For example, the filament yarn adds strength to thestaple yarns and thus facilitates processing as the core spun yarn issubjected to the twisting, heat setting and untwisting steps of thefalse twisting operation. This added strength makes it possible toeffectively work with staple fibers of various lengths, whether shortlong.

The continuous filament core used herein can be of any conventionaltype, e.g., nylon, polyester, acrylic or the like as long as it hassuitable shrinkage characteristics and enough strength to support thestaple fibers for the false twisting. While a nonthermoplastic filamentcore can be used and will give a satisfactory stretch yarn after falsetwisting, thermoplastic filament core yarns add even more desirablestretch properties and are preferred. In either case, the core which isused may be a monofilament or multifilament yarn.

It will be realized that the stretch yarn of the invention may be usedas such to prepare woven or knitted fabrics of varying constructions.The yarn may also be plied with another stretch yarn, which may have thesame or different composition and construction. Similarly, multiple endsof the core spun yarn may be plied together for false twisting withadvantage. However, it will be appreciated that the effective processingof single ends according to the invention is of particular importancesince the amount of labor and waste material is very substantiallyreduced from prior techniques involving the processing of single ends.

The invention is illustrated by the following:

A core of preferably fine;v denier, continuous filament 10-15 deniermonofilament nylon yarn), is inserted into a conventional spinning framedirectly behind the front roll. where the continuous. filament yarn isunited with staplefibers (e.g., wool fibers, a 40:60% blend withpolyester staple orlothertype blend, as described in the above-mentionedSer. No'. 423,256) which are being drafted in the draft zone to thedesired weight or count. It is important that proper tension (e.g., 5-20grams) be applied to the filament yarn-in order for the filament to bein a firm position with respect to the staple fibers. For best results,the filament, in the case of double roving, shouldvbe in the center ofthe two rovings. However, when: using single roving, the filament shouldbe on the left side of the roving for Z twist yarn and on the right sidefor the S yarns for the best coverage with staple fibers. This methodreduces grin-through of the filament core.

After the yarn is spun, it is conditioned on a spinning bobbin (e.g., ata dry bulb temperature of 8090 C. and a wet bulb of 7080 C.) for sixtyminutes to set the yarn and reduce the tendency to kink in thetexturizing process that follows. The yarn after conditioning is thenwound on a cone ready for the texturizing or false twist/heat-setprocess. As the yarn is unwound off the cone, it is laced through aseries of tension devices for proper tension, then through the heat-setchamber at a temperature of around -245 C. at a speed of about 10-70yards/minute with a heat exposure time of about 0.2 second to 5.0seconds per linear inch of yarn. From the heater element,-yarn is fedinto the false twist rotor which usually revolves at a speed of between20,000 and 150,000 r.p.m. From the false twist spindle, the yarn iswound onto a takeup package ready for use.

The drawings attached hereto illustrate diagrammatically the preparationof the core spun yarn (FIGURE 1) and the false twisting or texturizingof the core spun yarn (FIGURE 2).

According to FIGURE 1, the filament core yarn 2 is fed from anappropriate supply 3 through tension guides 4 into the staple fibers 6behind the front rolls 8 of a conventional spinning frame F. The staplefibers 6 are drafted in zone '10 of the spinning frame and the resultingcore spun yarn 11 is taken up in usual fashion on the spinning bobbin12. Following conditioning as aforesaid, the yarn is ready for the falsetwisting operation which, according to the embodiment shown in FIGURE 2,involves passing the spun core yarn 11 from its package 14 through acentering eye 16, to tensioning means 18, and overfeed roll 20. From theroll 20, the yarn is passed through the heat-set chamber or heating zone22, false twist rotor 24, and traverse guide 26 onto takeup package 28.The resulting stretch yarn may then be used as desired in weaving fabricor otherwise.

Having described the invention, what is claimed as new is:

1. A process for producing a stretch yarn which comprises preparing acore spun yarn made up of a core of continuous filament yarn coveredwith staple fibers in a uniform way without dimensional decorativeeffects, and thereafter false twisting and heat setting said core spunyarn.

2. The process of claim 1 wherein the continuous filament corn yarn isthermoplastic.

3. The process of claim 2 wherein thestaple fibers comprisenonthermoplastic fibers.

6. The stretch yarn obtained by the process of claim 1.

7. The stretch yarn of claim 6 wherein said core is overed withnonthermoplastic staple fibers.

8. A process according to claim ,1 wherein the core pun yarn is preparedby inserting a 10-15 denier monolament nylon yarn into a roving ofstaple wool fibers as aid fibers are being drafted on a spinning frame,after ihich the resulting core spun yarn is taken up On a spiningbobbin, conditioned and then subjected to false wisting.

References Cited UNITED STATES PATENTS Breen et al 57-139 Stoddard eta1. 57-l56 Baebler 57140 Gliksmann et a1 2872 Rapoza 57---144 XRGliksmann et al. 57-157 Reid et al. 57163 Fairley 57 15.7 XR

US. Cl. X.R.

